Traditional approaches for isolating pathogenic agents have been unsuccessful in a substantial number of disease conditions where an infectious etiology is suspected, e.g., Crohn's disease, ulcerative colitis, Wegener's granulomatosis, rheumatoid arthritis, tropical sprue, systemic lupus erythrematosus, Kawasaki's disease, and other chronic diseases (Costeron et al., (1999) Science 284:1318; Relman, (1999) Science 284:1308). Use of broad range PCR or other molecular approaches (e.g., microarrays) have been suggested to identify the causative agent underlying infectious disease states (Fredricks et al., (1999) Clin. Infect. Dis. 29:475; Relman, (1999) Science 284:1308; Cummings et al., (2000) Emerg. Infect. Dis. 6:513; Diehn et al., (2001) Curr. Opin. Microbiol 4:95). However, these approaches do not result in isolation of the organism for use in further studies and are cumbersome for many experimental applications (e.g., antimicrobial and disease studies and/or vaccine development).
Microorganisms may be introduced into mammalian subjects by a variety of mechanisms, including inhalation, ingestion, severe or persistent insect bites, injections, prolonged use of saline needles, implantation of medical devices, or exposure during surgical techniques. The introduced organisms may have an affinity for red blood cells (RBCs) or nerve cells and may even grow in these cells. Infections may be particularly severe in the case of immunocompromised patients, such as those on immunosuppressive drugs, infected with HIV, or having particular genetic conditions. In addition, certain patients, such as those with diabetes or cystic fibrosis, are particularly susceptible to infection (Ahkee et al., (1995) J. Ky. Med. Assoc. 93:511; Costeron, (2001) Trends Microbiol 9:50; Costeron et al., (1999) Science 284:1318). For example, it is known that cystic fibrosis patients, who suffer a defect in the chloride transport system, are susceptible to infection with Ps. aeruginosa, as well as other microorganisms. In these patients, antibodies to alkaline phosphatase, exotoxin A, and elastase of Ps. aeruginosa have been detected (Costeron, (2001) Trends Microbiol 9:50; Costeron et al., (1999) Science 284:1318).
Various gram-negative urinary tract or local skin flora may gain entrance into the body, e.g., due to insect bites, wounds, injuries and the like, causing infection in synovial fluids and joint inflammation. Moreover, Streptococcus spp. and Staphylococcus spp. are frequently linked to disease (Costeron et al., (1995) Annu. Rev. Microbiol. 49:711). Infections by some agents are facilitated by insect transmission, for example, Bartonella spp. infections transmitted by fleas, lice or ticks are introduced into cats, dogs, humans and other mammals (see, e.g., Shaw et al., (2001) Trends Parasitol. 17:74; Munana et al. (2001) Infect. Immun. 69:564; Breitschwerdt et al., (2000) Clin. Microbiol Rev. 13:428).
Microorganisms may cause pathology in multiple organs or tissues in the host, not because of direct invasion or growth in the affected tissues, but rather as a result of molecular mimicry between self-antigens and microbial cell antigens, which induces immune-mediated tissue destruction. Molecular mimicry between bacterial or viral proteins and endogenous molecules has been implicated in various autoimmune diseases, including insulin dependent diabetes mellitus, Gillian Barre syndrome, multiple sclerosis and autoimmune herpes stromal keratitis (Relman, Science 284:1308). After initiation of the disease, epitope spreading leads to the maintenance and progression of inflammation.
Bartonella are vector-transmitted, blood-borne, intracellular gram-negative bacteria that can induce prolonged infection in the host. Persistent infections in domestic and wild animals result in a reservoir of Bartonella in nature that can serve as a source for human infection. The prevalence can range from 50–95% in selected rodent, cat, deer or cattle populations. Considering the extensive animal reservoirs and the large number of insects that have been implicated in the transmission of Bartonella spp., both animal and human exposure to these organisms may be more substantial than is currently realized.
Recent observations support a role for Bartonella as animal as well as human pathogens. Dogs infected with Bartonella spp. can develop lameness, endocarditis, granulomatous lymphadenitis and peliosis hepatis, lesions that are also reported in association with human infection. In felines, recent reports describe a correlation between Bartonella seroreactivity and renal disease, stomatitis, or lymphadenopathy.
The spectrum of diseases attributable to Bartonella spp. now includes lymphadenopathy (i.e., cat scratch disease or CSD), bacillary angiomatosis, bacillary peliosis, bacteremia, endocarditis, myositis, retinitis, endocarditis, bacillary angiomatosis, osteolysis, polyarthritis, leukoclastic vasculitis, fever of unknown origin (Trench Fever) and hemolytic anemia (South American bartonellosis). Bartonella bacilliformis, B. quintana, B. elizabethae, B. vinsonii subspecies arupensis., B. clarridgeiae and B. henselae have been associated with these disease manifestations in human patients (Anderson et al., (1997) Clin. Microbiol. Rev. 10:203).
In addition, a new α-2 proteobacterium, provisionally designated Rasbo bacterium, has been isolated from a human patient with evidence of myocardial disease. B. quinitana, which is transmitted by the human body louse, is the infectious agent underlying epidemics of trench fever during World War I. There also appears to be a correlation between Bartonellosis and renal disease in human patients.
Recently, a novel Bartonella subspecies, designated as B. vinsonii subspecies berkhoffi (ATTC strain 51672) has been identified. In one study, cardiac arrhythmias, endocarditis, or myocarditis was observed in 12 dogs, 11 of which were seroreactive to B. vinsonii subsp. berkhoffi antigens. It appears that B vinsonii subsp. berkhoffi and closely-related species of alpha-proteobacteria may be an important, previously unrecognized, cause of arrhythmias, endocarditis, myocarditis, syncope, and sudden death in dogs.
There is also increasing evidence that several Bartonella spp., including B. quintana, B. elizabethae, B. vinsonii and B. henselae are responsible for cases of culture-negative endocarditis in human patients. A retrospective study from France identified patients with bartonella endocarditis that had not previously been diagnosed using conventional microbiologic techniques. To date, bartonella endomyocarditis in dogs has only been associated with B. vinsonii (berkhoffii); however, the inventors' laboratory has obtained molecular evidence of B. henselae infection in a dog with peliosis hepatis (Kitchell et al., (2000) J. Am. Vet Med. Assoc. 216:519), a liver lesion that has recently been associated with either B. henselae or B. quintana infection in human patients. Not only does this observation provide the first microbiologic or molecular evidence for persistent B. henselae infection in dogs, it also indicates that B. henselae might be implicated in future studies of culture-negative endocarditis in dogs.
In human patients, bartonella endocarditis has been reported in children and in adults, particularly homeless individuals with exposure to B. quintana as a result of louse infestation. Bartonella endocarditis has also been reported in association with immune-complex glomerulonephritis. Recently, it has been reported that infection due to Bartonella weisii species in North Carolina beef cattle (Breitschwerdt et al., (2001) J. Clin. Microbiol 39:879).
Further, Chlamydia trachomatis, Ch. psittaci, and Ch. pneumoniae have been linked to heart disease. Infection with Ch. trachomatis has been reported to result in the production of auto-antibodies to heart muscle specific epitopes. Other Chlamydia spp. bear epitopes that are similar to heart proteins (Bachmaier et al., (1999) Science 283:1335). Similarly, in patients with multiple sclerosis, antibodies to C. pneumoniae are routinely detected, but this microorganism has not yet been isolated from these patients. Further, in patients with Crohn's disease or ankylosing spondylitis, Klebsiella pneumoniae antibodies are directed against collagen types I, III, IV and V.
Accordingly, there is a need in the art for improved media for culturing and isolating microorganisms. Moreover, there is a need in the art for improved methods of culturing, detecting and identifying these, and other, microorganisms that are associated with animal and human disease.